In race for 4G spectrum, don’t write off satellite
By Caroline Gabriel, Research Director, Maravedis-Rethink
As mobile networks start to run out of capacity in their traditional spectrum bands, vendors and operators are looking for new frequencies for radio to colonize, and their eyes often light on satellite space. Initially the focus was on mobile satellite (MSS) spectrum close to the existing mobile bands, and the reuse of such assets for radio has been one of the most important, but contentious, aspects of the recent quest for new mobile capacity. Now major players are also casting their eyes over more distant satellite territories, as seen in Samsung’s recent announcement of ‘5G’ technology, which achieved 1Gbps transmission speeds in the 28GHz Ka band, mainly used for fixed satellite uplink.
The use of these high frequency, millimeter wave bands for radio access remains controversial, though there is considerable progress in harnessing this spectrum for backhaul. Initiatives like Samsung’s experiment, or the WiGig standard – which runs a Wi-Fi variant in 60GHz – show how seriously high frequency access is now being taken. This is especially driven by the trend to build layers of very small cells in mobile broadband networks, as these get around one of the key disadvantages of high bands, their short range.
So more generally, do such trends imply that the satellite communications business is a dying one, and eventually its spectrum will be largely conquered by radio? Cellular technologies are getting better at expanding into the rural areas where satellite broadband has thrived, and regulators like the UK’s Ofcom have high hopes for emerging long-range options like white spaces networks as an lower cost, higher speed alternative to satellite. Last week saw a Qualcomm proposal to the US FCC, to use the Ku band satellite spectrum for a radio-based air-to-ground system which could compete with in-flight satellite services like GoGo. But set against that is the imminent launch of ViaSat-2, which promises a massive step forward in capacity and speed, and whose backers insist will more than justify its cost in terms of new communications services.
Outgoing FCC chairman Julius Genachowski has certainly not been a friend to the satellite communications sector. In his quest to free up a huge swathe of new spectrum for mobile broadband, he has seen some of the satellite bands as easy pickings. Sometimes the FCC’s eagerness has been disastrous, as seen in the LightSquared fiasco. Insufficient care was taken to address the interference concerns of the GPS players, whose frequencies sit just above the start-up’s L-band (1.5GHz) MSS spectrum, and LightSquared ended up in bankruptcy protection.
However, a similar plan by Dish Network to use frequencies formerly reserved for MSS – in the AWS-4 portion of the 2GHz band – has been approved. And Genachowski recently said he still believes the L-band will be usable in future, with technology changes to protect GPS.
Such comments, which seemed to downplay the complexity of those changes, highlighted the retiring chairman’s firm belief that all satellite (and broadcast) spectrum is underused and should be reallocated for, or shared with, terrestrial mobile broadband services. For instance, the Satellite Industry Association responded angrily last month to his proposals that the 3.5GHz C-band should be allocated to small cells (though these would have to coexist with existing users). The SIA said it had concerns over “whether introduction of small cells in the 3.5 GHz band would be compatible with current and future satellite operations” and added it had “significant disagreement on virtually every aspect of the regulatory framework” proposed by the FCC, and expressed “doubts about whether the proposals for shared access to the band are feasible, particularly in the near term”.
Undoubtedly, spectrum sharing techniques are improving all the time – the TV white spaces projects have been an important testing ground – and mobile satellite bands have been underused. However, there are fears that some regulators are belittling the technical and political issues that are involved in the near term, and are disregarding the commercial potential that still lies in satellite broadband.
This is best demonstrated by ViaSat, which answered critics who claim there is no profit model in satellite broadband recently, when it returned to the black and reported a 28% year-on-year increase in first quarter revenues, crediting a rise in broadband subscribers in the residential, broadband and airline sectors. It sees sufficient growth potential to have launched a mighty satellite, ViaSat-1, recently, and to plan a second, upgraded bird, ViaSat-2, in 2016.
The former has total capacity of 140Gbps, which supports the firm’s Exede broadband service for remote and rural areas of north America as well as in-flight connectivity. Via-Sat 2 will enable twice the capacity and a sevenfold increase in coverage. Exede offers services of 12Mbps, comparable to Verizon’s recently announced fixed LTE offering, HomeFusion, which promises rates between 5Mbps and 12Mbps. Verizon and, in particular, AT&T have indicated they will use LTE to phase out DSL, in areas where they do not have fiber coverage, but AT&T still relies on satellite in ultra-rural areas, and there are no indications that will change.
Across the Atlantic, the European Union calculates that almost 10m households have no access to broadband – over 95% of European homes are connected, but the figure falls to 78.4% in rural regions. Despite putting LTE and unlicensed wireless systems at the heart of universal coverage projects, the EU still sees a significant role for satellite, as witnessed by its SABER (satellite broadband for European regions) program. This aims to set out a framework for authorities to use satellite to achieve 100% broadband coverage objectives by 2020, and has received €510,000 in EU funding.
In other words, while satellite spectrum will certainly be a valuable source of additional capacity for mobile networks in future, regulators should not be too hasty – while the wireless industry’s voice is loud and frequently rational, agencies like the FCC must recognize the continuing role for satellite and, while working on important breakthroughs in spectrum sharing, must also guard against disasters like the LightSquared episode, which only serve to put valuable frequencies into limbo.